Nonamethine dyes



Patented Aug. 13, 1940 UNITED STATES azure NONAMETHINE DYES Walter Dieterle and Oskar Riester, Dessau- Ziebigk, Germany, assignors, by mesne assignments, to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application March 1, 1938, Serial No. 193,287. In Germany March 6, 1937 Claims.

This invention relates to nonamethine dyestuffs.

Anilino-nonamethine dyestuffs in which a carbon atom of the polymethine chain is united instead of with a hydrogen atom with an oxacyl group are produced as described in'W. Konig, Berichte der deutschen Chemischen Gesellschaft, 67, 1934, pages 1274 et seq., especially page 1288, upper part. These known oxacyl-substituted nonamethine dyestuffs serve as the material for producing sensitizing undeca-methinecyanines which obviously also contain the oxacyl group. It is now known (Zeitschrift fiir wissenschaftliche Photographic, vol. 34, 1935, page 249) that polymethine dyestuffs having an oxacyl group are three to four times lesseffective as sensitizers than the analogous dyestuffs not containing the oxacyl group. Therefore, it is of technical importance to produce nonamethine dyestuffs without oxacyl groups. Their conversion into undeca-methinecyanines follows known processes.

One object of this invention is to provide a process of producing new nonamethine dyes without oxacyl groups in the polymethine chain.

Another object isto produce the new dyestuffs themselves.

Further objects will be seen from the following detailed specification,

This invention is basedon the observation that anilino-nonamethine dyestuffs are produced by causing glutaconic acid in presenceof a condensing agent of acid character to act on an unsaturated aldehyde of the general formula stands for the radical of a secondary amine (wherein R1 is alkyland R2 is aryl), or

is used for the formation of the dyestuif salt. The course of the reaction is as follows:

It is, however, to be noted that this scheme of reaction is not put forward as final; the essence is, that in the reaction a methine dyestuff is produced which, according to the existing knowledge concerning methine dyestuffs, must go be supposed to contain a chain of 9 methine groups.

The best yields are obtained in starting from an aldehyde whose aniline radical is containedin a ring system including a nitrogen atom. The original amine is then, a heterocyclic basefor example, tetrahydroquinoline, dihydro-a-methyla indole, a-methylphenmorpho1ine The production of the necessary aldehyde of the general formula given above is described in British Patent No. 485,624. I

The following examples serve to illustrate the invention: Example 1.--3.75 grams of tetrahydroquinoline-N-propenal of the formula 1%[2 $2 I (3-0 are dissolved in 5.5 cc. of glacial acetic acid and 1.5 cc. of acetic anhydride at about 30 C. The vessel containing the solution is placed in a water bath at 30 C. In the course of about 90 minutes l gram of glutaconic acid is introduced in quite small doses. After each addition the whole is strongly stirred, The solution thus becomes brown, then green. After about an hour a mix ture of 1 cc. of a glacial acetic acid and 0.2 cc. of acetic anhydride is added. When nearly all the glutaconic acid has been added crystallizationbegins, the substance separating being a by-prod-' not which can be recognized by the'appearancethat of Example 1.

of a blue-grey deposit on the glass wall. A few minutes after the introduction of the last dose the whole is filtered and the deep grass green filters. They are also useful for producing undeca-methinecyanines by means of which photographic layers are advantageously sensisolution receives an addition of potassium iodide tized for infra-red. Their conversion into to precipitate the dyestuif. The crude dyestuif undeca-methinecyanines follows known procthus produced has the formula esses.

l i PIT: 1' 2 1?: (3-0 oo H20 NCH=CH-CH=OH-CH=GHOH=CHCH=N H2 It is filtered with suction, extracted with benzene in a Soxhlet apparatus and dried. It is a dull green powder soluble in methanol to a green solution. Its maximum absorption is at about 6850 A. U.

The dyestuif may be purified by crystallization from methanol solution, the losses, however, be ing somewhat great. The recrystallized dyestuif dissolves to a sky-blue solution. It shows no violet absorption which is still perceptible in the unpurified dyestuif.

Example 2.-Instead of the aldehyde tetrahydroquinoline-N-propenal there may be used the aldehyde monomethyl-aniline N propenal. The course of the reaction is quite analogous with The yields are, however, poorer. The dyestuff thus obtained has the following formula C0115 I can Example 3.If the aldehyde Z-methylphenmorpholine-N-propenal is used, the yield is about the same as in Example 1. The dyestufi produced has the formula 0 o om HzC Example 4.Instead of the aldehyde tetrahydroquinoline-N-propenal as described in Example 1 there may be used analogous to the manner described in Example 1 the aldehyde dihydro-e-methyl-indole-N-propenal. The dyestuff obtained has the following formula Obviously the process is not limited to the proportions and temperatures named in the specification. The expert will vary these data from case to case, for example the temperatures may be far lower than those given.

The new class of dyestuffs is principally useful for dyeing, for example, acetate artificial silk. The main application, however, is in photography. Thus the dyestuffs may be used for making light What we claim is:

1. A process of producing nonamethine dyes corresponding with the general formula R1 /R1 second position of the aromatic nucleus ortho to the first, comprising causing an unsaturated aldehyde corresponding with the formula R1 0 NCH=CHC R: H

to react with glutaconic acid in the presence of a condensing agent of acid character.

2. A process of producing nonamethine dyes comprising causing unsaturated aldehydes selected from the class consisting of tetrahydroquinoline-N-propenal, dihydroa-methyl-indole- N-propenal to react with gluetaconic acid in the presence of a condensing agent of acid character.

3. A process of producing a nonamethine dye corresponding with the formula comprising causing an aldehyde corresponding with the formula to react with glutaconic acid in the presence of a condensing agent of acid character, and precipitating the dyestufi with potassium iodide.

4. A process of producing a nonamethine dyestuff corresponding with the formula comprising causing an aldehyde corresponding with the formula to react with glutaconic acid in the presence of a condensing agent of acid character, and precipitating the dyestuff with potassium iodide.

5. A process of producing a nonamethine dyestuff corresponding with the formula comprising causing an aldehyde corresponding with the formula to react with glutaconic acid in the presence of a condensing agent of acid character, and precipitating the dyestufi with potassium iodide.

6. -A nonamethine dyestuff corresponding with the general formula is selected from the class consisting of radicals of secondary amines (wherein R1 is alkyl and R2 is aryl) and radicals of heterocyclic rings including the nitrogen atom and condensed with an aromatic nucleus, said nitrogen atom being bonded directly to one position of the aromatic nucleus and through a saturated chain to a second position of the aromatic nucleus ortho to the first.

7. A nonamethine dyestufi corresponding with the general formula is selected from the class consisting of monoalkylaniline, tetrahydroquinoline, dihydro-a-alkylindole, and a-alkylphenmorpholine.

8. A nonamethine dyestuff having the following formula CH:CHCH=CHCH=CHCH=CH-CH 10. A nonamethine dyestuff having the following formula WALTER DZIETERLE. OSKAR RIESTER. 

